/* zmalloc - total amount of allocated memory aware version of malloc()
 *
 * Copyright (c) 2009-2010, Salvatore Sanfilippo <antirez at gmail dot com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of Redis nor the names of its contributors may be used
 *     to endorse or promote products derived from this software without
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>

/* This function provide us access to the original libc free(). This is useful
 * for instance to free results obtained by backtrace_symbols(). We need
 * to define this function before including zmalloc.h that may shadow the
 * free implementation if we use jemalloc or another non standard allocator. */
void zlibc_free(void *ptr) {
    free(ptr);
}

#include <string.h>
//#include <pthread.h>
//#include "config.h"
#include "zmalloc.h"

#ifdef HAVE_MALLOC_SIZE
#define PREFIX_SIZE (0)
#else
#if defined(__sun) || defined(__sparc) || defined(__sparc__)
#define PREFIX_SIZE (sizeof(long long))
#else
#define PREFIX_SIZE (sizeof(size_t))
#endif
#endif

/* Explicitly override malloc/free etc when using tcmalloc. */
//#if defined(USE_TCMALLOC)
//#define malloc(size) tc_malloc(size)
//#define calloc(count,size) tc_calloc(count,size)
//#define realloc(ptr,size) tc_realloc(ptr,size)
//#define free(ptr) tc_free(ptr)
#if defined(USE_JEMALLOC) //#elif defined(USE_JEMALLOC)
#define malloc(size) je_malloc(size)
#define calloc(count,size) je_calloc(count,size)
#define realloc(ptr,size) je_realloc(ptr,size)
#define free(ptr) je_free(ptr)
#endif

//#if defined(__ATOMIC_RELAXED)
//#define update_zmalloc_stat_add(__n) __atomic_add_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
//#define update_zmalloc_stat_sub(__n) __atomic_sub_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
//#elif defined(HAVE_ATOMIC)
//#define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
//#define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
//#else
//#define update_zmalloc_stat_add(__n) do { \
//    pthread_mutex_lock(&used_memory_mutex); \
//    used_memory += (__n); \
//    pthread_mutex_unlock(&used_memory_mutex); \
//} while(0)
//
//#define update_zmalloc_stat_sub(__n) do { \
//    pthread_mutex_lock(&used_memory_mutex); \
//    used_memory -= (__n); \
//    pthread_mutex_unlock(&used_memory_mutex); \
//} while(0)
//
//#endif

//#define update_zmalloc_stat_alloc(__n) do { \
//    size_t _n = (__n); \
//    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
//    if (zmalloc_thread_safe) { \
//        update_zmalloc_stat_add(_n); \
//    } else { \
//        used_memory += _n; \
//    } \
//} while(0)
#define update_zmalloc_stat_alloc(__n) do { \
    size_t _n = (__n); \
    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
    used_memory += _n; \
} while(0)

//#define update_zmalloc_stat_free(__n) do { \
//    size_t _n = (__n); \
//    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
//    if (zmalloc_thread_safe) { \
//        update_zmalloc_stat_sub(_n); \
//    } else { \
//        used_memory -= _n; \
//    } \
//} while(0)
#define update_zmalloc_stat_free(__n) do { \
    size_t _n = (__n); \
    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
    used_memory -= _n; \
} while(0)

static size_t used_memory = 0;
//static int zmalloc_thread_safe = 0;
//pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;

static void zmalloc_default_oom(size_t size) {
    fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
        size);
    fflush(stderr);
    abort();
}

static void (*zmalloc_oom_handler)(size_t) = zmalloc_default_oom;

void *zmalloc(size_t size) {
    void *ptr = malloc(size+PREFIX_SIZE);

    if (!ptr) zmalloc_oom_handler(size);
#ifdef HAVE_MALLOC_SIZE
    update_zmalloc_stat_alloc(zmalloc_size(ptr));
    return ptr;
#else
    *((size_t*)ptr) = size;
    update_zmalloc_stat_alloc(size+PREFIX_SIZE);
    return (char*)ptr+PREFIX_SIZE;
#endif
}

void *zcalloc(size_t size) {
    void *ptr = calloc(1, size+PREFIX_SIZE);

    if (!ptr) zmalloc_oom_handler(size);
#ifdef HAVE_MALLOC_SIZE
    update_zmalloc_stat_alloc(zmalloc_size(ptr));
    return ptr;
#else
    *((size_t*)ptr) = size;
    update_zmalloc_stat_alloc(size+PREFIX_SIZE);
    return (char*)ptr+PREFIX_SIZE;
#endif
}

void *zrealloc(void *ptr, size_t size) {
#ifndef HAVE_MALLOC_SIZE
    void *realptr;
#endif
    size_t oldsize;
    void *newptr;

    if (ptr == NULL) return zmalloc(size);
#ifdef HAVE_MALLOC_SIZE
    oldsize = zmalloc_size(ptr);
    newptr = realloc(ptr,size);
    if (!newptr) zmalloc_oom_handler(size);

    update_zmalloc_stat_free(oldsize);
    update_zmalloc_stat_alloc(zmalloc_size(newptr));
    return newptr;
#else
    realptr = (char*)ptr-PREFIX_SIZE;
    oldsize = *((size_t*)realptr);
    newptr = realloc(realptr,size+PREFIX_SIZE);
    if (!newptr) zmalloc_oom_handler(size);

    *((size_t*)newptr) = size;
    update_zmalloc_stat_free(oldsize);
    update_zmalloc_stat_alloc(size);
    return (char*)newptr+PREFIX_SIZE;
#endif
}

/* Provide zmalloc_size() for systems where this function is not provided by
 * malloc itself, given that in that case we store a header with this
 * information as the first bytes of every allocation. */
#ifndef HAVE_MALLOC_SIZE
size_t zmalloc_size(void *ptr) {
    void *realptr = (char*)ptr-PREFIX_SIZE;
    size_t size = *((size_t*)realptr);
    /* Assume at least that all the allocations are padded at sizeof(long) by
     * the underlying allocator. */
    if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
    return size+PREFIX_SIZE;
}
#endif

void zfree(void *ptr) {
#ifndef HAVE_MALLOC_SIZE
    void *realptr;
    size_t oldsize;
#endif

    if (ptr == NULL) return;
#ifdef HAVE_MALLOC_SIZE
    update_zmalloc_stat_free(zmalloc_size(ptr));
    free(ptr);
#else
    realptr = (char*)ptr-PREFIX_SIZE;
    oldsize = *((size_t*)realptr);
    update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
    free(realptr);
#endif
}

char *zstrdup(const char *s) {
    size_t l = strlen(s)+1;
    char *p = zmalloc(l);

    memcpy(p,s,l);
    return p;
}

size_t zmalloc_used_memory(void) {
    size_t um;

//    if (zmalloc_thread_safe) {
//#if defined(__ATOMIC_RELAXED) || defined(HAVE_ATOMIC)
//        um = update_zmalloc_stat_add(0);
//#else
//        pthread_mutex_lock(&used_memory_mutex);
//        um = used_memory;
//        pthread_mutex_unlock(&used_memory_mutex);
//#endif
//    }
//    else {
        um = used_memory;
//    }

    return um;
}

//void zmalloc_enable_thread_safeness(void) {
//    zmalloc_thread_safe = 1;
//}

void zmalloc_set_oom_handler(void (*oom_handler)(size_t)) {
    zmalloc_oom_handler = oom_handler;
}

///* Get the RSS information in an OS-specific way.
// *
// * WARNING: the function zmalloc_get_rss() is not designed to be fast
// * and may not be called in the busy loops where Redis tries to release
// * memory expiring or swapping out objects.
// *
// * For this kind of "fast RSS reporting" usages use instead the
// * function RedisEstimateRSS() that is a much faster (and less precise)
// * version of the function. */
//
//#if defined(HAVE_PROC_STAT)
//#include <unistd.h>
//#include <sys/types.h>
//#include <sys/stat.h>
//#include <fcntl.h>
//
//size_t zmalloc_get_rss(void) {
//    int page = sysconf(_SC_PAGESIZE);
//    size_t rss;
//    char buf[4096];
//    char filename[256];
//    int fd, count;
//    char *p, *x;
//
//    snprintf(filename,256,"/proc/%d/stat",getpid());
//    if ((fd = open(filename,O_RDONLY)) == -1) return 0;
//    if (read(fd,buf,4096) <= 0) {
//        close(fd);
//        return 0;
//    }
//    close(fd);
//
//    p = buf;
//    count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
//    while(p && count--) {
//        p = strchr(p,' ');
//        if (p) p++;
//    }
//    if (!p) return 0;
//    x = strchr(p,' ');
//    if (!x) return 0;
//    *x = '\0';
//
//    rss = strtoll(p,NULL,10);
//    rss *= page;
//    return rss;
//}
//#elif defined(HAVE_TASKINFO)
//#include <unistd.h>
//#include <stdio.h>
//#include <stdlib.h>
//#include <sys/types.h>
//#include <sys/sysctl.h>
//#include <mach/task.h>
//#include <mach/mach_init.h>
//
//size_t zmalloc_get_rss(void) {
//    task_t task = MACH_PORT_NULL;
//    struct task_basic_info t_info;
//    mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
//
//    if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
//        return 0;
//    task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
//
//    return t_info.resident_size;
//}
//#else
//size_t zmalloc_get_rss(void) {
//    /* If we can't get the RSS in an OS-specific way for this system just
//     * return the memory usage we estimated in zmalloc()..
//     *
//     * Fragmentation will appear to be always 1 (no fragmentation)
//     * of course... */
//    return zmalloc_used_memory();
//}
//#endif
//
///* Fragmentation = RSS / allocated-bytes */
//float zmalloc_get_fragmentation_ratio(size_t rss) {
//    return (float)rss/zmalloc_used_memory();
//}
//
///* Get the sum of the specified field (converted form kb to bytes) in
// * /proc/self/smaps. The field must be specified with trailing ":" as it
// * apperas in the smaps output.
// *
// * Example: zmalloc_get_smap_bytes_by_field("Rss:");
// */
//#if defined(HAVE_PROC_SMAPS)
//size_t zmalloc_get_smap_bytes_by_field(char *field) {
//    char line[1024];
//    size_t bytes = 0;
//    FILE *fp = fopen("/proc/self/smaps","r");
//    int flen = strlen(field);
//
//    if (!fp) return 0;
//    while(fgets(line,sizeof(line),fp) != NULL) {
//        if (strncmp(line,field,flen) == 0) {
//            char *p = strchr(line,'k');
//            if (p) {
//                *p = '\0';
//                bytes += strtol(line+flen,NULL,10) * 1024;
//            }
//        }
//    }
//    fclose(fp);
//    return bytes;
//}
//#else
//size_t zmalloc_get_smap_bytes_by_field(char *field) {
//    ((void) field);
//    return 0;
//}
//#endif
//
//size_t zmalloc_get_private_dirty(void) {
//    return zmalloc_get_smap_bytes_by_field("Private_Dirty:");
//}
